LAS\ACCUMULATE ACCUMULATE is used to integrate step by step an ensemble of spectra. The T spectrum is added to the R spectrum with the current weights. R thus contains the current sum, and T the last sum. As command AVERAGE, ACCUMULATE checks for the positional coincidence and calibration homo- geneity according to SET MATCH and SET CALIBRATION respectively. Aligne- ment of spectra is checked according to SET ALIGN command. Accumulated spectra may have different spectral resolution. In this latter case, the final spectrum has the coarsest resolution of the two input spectra, and each channel will be the weighted average of the average values of each spectrum in the resulting channel. It is however preferable to accumu- late spectra which have the same resolution. For EQUAL weights, ACCUMULATE computes the sum of the two spectra, al- lowing addition of an ensemble of spectra after division by the total number of spectra. For other weightings, ACCUMULATE computes the average of the two spec- tra. ACCUMULATE also works on Continuum drift. The alignement may be Channel or Position in this case.Please consider that ACCUMULATE behaves differently if using an EQUAL weight or another one: this provides to the user a way to perform its own average by first adding the spectra and then dividing them at its will.